Rigid collars are made of a proprietary material and are designed to fill the bolt holes of the chassis which have loosened over time. When the car is brand new the chassis is tight and there is little movement between the panels of the car. This however does not last and over time the handling of the car becomes poor. Even with brand new aftermarket suspension and bushings installed the car will not perform to it’s best as this movement between panels is present. Here the rigid collar comes in to play. It is crushed in to place when the bolt is tightened and thus fills all the gaps in between the body frame’s panels and thus stops that movement forever. Get this and all your JDM at RHDJapan!!